Swift: Handle method and initializer key path components in QL

Note that it does not seem to be possible to write test that exercise this
code. Passing `-enable-experimental-feature KeyPathWithMethodMembers` to the
extractor results in:
```
error: experimental feature 'KeyPathWithMethodMembers' cannot be enabled in production compiler
```

Author: jketema

swift/ql/.generated.list

@@ -7,6 +7,11 @@ module Impl {
    * A component of a `KeyPathExpr`.
    */
   class KeyPathComponent extends Generated::KeyPathComponent {
+    /**
+     * Method or initializer application like `.bar` in `\Foo.bar` with `bar` a method.
+     */
+    predicate isApply() { this.getKind() = 4 }
+
     /**
      * Property access like `.bar` in `\Foo.bar`.
      */

swift/ql/lib/codeql/swift/elements/internal/KeyPathComponentImpl.qll

@@ -2,17 +2,18 @@ import codeql.swift.elements
 import TestUtils
 
 from
-  KeyPathComponent x, string property, string subscript, string opt_forcing, string opt_chaining,
-  string opt_wrapping, string self, string tuple_indexing
+  KeyPathComponent x, string apply, string property, string subscript, string opt_forcing,
+  string opt_chaining, string opt_wrapping, string self, string tuple_indexing
 where
   toBeTested(x) and
   not x.isUnknown() and
+  (if x.isApply() then apply = "apply" else apply = "") and
   (if x.isProperty() then property = "property" else property = "") and
   (if x.isSubscript() then subscript = "subscript" else subscript = "") and
   (if x.isOptionalForcing() then opt_forcing = "optional forcing" else opt_forcing = "") and
   (if x.isOptionalChaining() then opt_chaining = "optional chaining" else opt_chaining = "") and
   (if x.isOptionalWrapping() then opt_wrapping = "optional wrapping" else opt_wrapping = "") and
   (if x.isSelf() then self = "self" else self = "") and
   if x.isTupleIndexing() then tuple_indexing = "tuple indexing" else tuple_indexing = ""
-select x, "getKind:", x.getKind(), property, subscript, opt_forcing, opt_chaining, opt_wrapping,
-  self, tuple_indexing
+select x, "getKind:", x.getKind(), apply, property, subscript, opt_forcing, opt_chaining,
+  opt_wrapping, self, tuple_indexing

swift/ql/lib/codeql/swift/generated/KeyPathComponent.qll

@@ -490,15 +490,13 @@ class KeyPathComponent(AstNode):
     kind: int | doc("kind of key path component") | desc("""
         INTERNAL: Do not use.
 
-        TODO: Swift 6.2 update with UnresolvedApply and Apply
+        This is 4 for method or initializer application, 5 for members, 6 for array and dictionary
+        subscripts, 7 for optional forcing (`!`), 8 for optional chaining (`?`), 9 for implicit
+        optional wrapping, 10 for `self`, and 11 for tuple element indexing.
 
-        This is 5 for properties, 6 for array and dictionary subscripts, 7 for optional forcing
-        (`!`), 8 for optional chaining (`?`), 9 for implicit optional wrapping, 10 for `self`,
-        and 11 for tuple element indexing.
-
-        The following values should not appear: 0 for invalid components, 2 for unresolved
-        properties, 3 for unresolved subscripts, 12 for #keyPath dictionary keys, and 13 for
-        implicit IDE code completion data.
+        The following values should not appear: 0 for invalid components, 1 for unresolved
+        method or initializer applications, 2 for unresolved members, 3 for unresolved subscripts,
+        12 for #keyPath dictionary keys, and 13 for implicit IDE code completion data.
     """)
     subscript_arguments : list[Argument] | child | doc(
         "arguments to an array or dictionary subscript expression")